Table1. A summary across five core affective and cognitive functions with regard to: a) disruption in PTSD and related neural correlates; b) neuroscientific evidence of the impact of culture; and c) synthesis and hypothesis-generating suggestions for how culture might influence the neural processes affected in PTSD

	Neural and psychological substrates underpinning PTSD	Neural and psychological mechanisms influenced by culture	Suggestions for cultural differences in the neural processes affected in PTSD
1. Fear processing and regulation	Threat neurocircuitry alterations: impairments in MPFC regulation over subcortical threat detection networks, including amygdala, hippocampus; Reduced capacity to regulate strong negative emotions; impaired fear learning and extinction; increased negative appraisals and cognitions; Impairments in MPFC and hippocampal functioning could reflect reduced contextual processing.	Amygdala responses to fear faces modulated by cultural differences in individualistic versus collectivistic self-representation; Collectivistic cultural groups demonstrate restricted eye tracking to faces and utilise contextual cues to inform appraisals of affective information; Suppression regulation strategies detrimental to functioning in individualistic groups but beneficial to functioning in collectivistic groups.	Threat neurocircuitry disruptions and arousal mechanisms may be modulated by culture in PTSD, depending on the cultural relevance of the triggering stimulus; Emotion dysregulation following trauma may be modulated by culturally preferred emotion regulation strategies; Impaired contextual processing in PTSD may differentially impact those from collectivistic cultures.
2. Attentional biases to threat	Inefficient attentional resource allocation; Problems with disengaging from threat, hypervigilance to threat, and avoidance of threat associated with dysregulated cognitive control–emotional neural systems; Involves interaction between amygdala, dorsal frontoparietal attentional control networks, and dysregulated VLPFC and dACC activity.	Collectivistic cultural groups perceptually biased to attend to context/background cues; Individualistic cultural groups attend to local, salient, central cues; Reflected in cultural differences in engagement in place versus object processing regions in the brain.	Pre-existing cultural biases towards attending to central or gist-based versus contextual cues may influence how traumatic events are encoded, and the employment of attentional narrowing processes during high arousal; Disruption to attentional shifts in PTSD may also be affected by cultural preference.
3. Autobiographical and emotional memory	Intrusive trauma-related memory results from a breakdown in connections between medial temporal lobe (hippocampus) and medial prefrontal cortex (VMPFC); Under conditions of high arousal, a memory trade off with enhanced memory for centralised gist-related content versus reduced recall of peripheral details is underpinned by interconnections in the emotional memory network (e.g., amygdala, hippocampus, fusiform gyrus, inferior frontal gyrus); Overgeneralisation of autobiographical memories which has been associated with the hippocampus and abnormalities of the MPFC.	Intrusions are diminished if trauma encoding is self-related in individualists or other-related in collectivists; Cultural differences in attention allocation impacts on memory for central versus peripheral events; Autobiographical memories are focused on general social interactions and others amongst collectivists; individualist's memories are biased towards self-related, specific episodes.	The genesis and content of intrusive memories in PTSD, and the neural processes underpinning this, may be fundamentally influenced by cultural differences in memory construction; Cultural differences in deployment of attentional resources may impact how trauma events are encoded, as well as consolidated and retrieved in PTSD, modulating the memory trade-off effect; While one study has shown similar disruptions to autobiographical memory between cultural groups with PTSD, there has been very little investigation of how autobiographical memories and related neural processes are impacted by collectivist biases towards context and others.
4. Self-referential processing	Disturbances to self-referential processing and identity in PTSD, reflected in dysregulated MPFC, precuneus, and retrosplenial cortical functioning, as well as disorganised connectivity within the default mode network.	Individualists are biased towards self; collectivists are biased to considering self in relation to others; Culture shapes self-regulation systems in the brain: reflected in MPFC function during self-versus-other referential processing and judgements; Culture also influences the neural substrates of empathy and social evaluation.	Disruptions to self-referential systems may be distinct in PTSD sufferers with collectivistic cultural backgrounds, reflecting predominant other-focusedness.
5. Interpersonal processing and attachment	Disruption to interpersonal processing and attachment relationships in PTSD; Attachment cues may assist in alleviating PTSD symptoms, including attentional biases to threat and alleviating stress and social pain.	Cultural differences have been shown in the benefit afforded by types of social support, impacting on both the psychological and physiological mechanisms of stress; Cultural differences have also been demonstrated in the nature of support seeking during stress.	Cultural factors may influence how attachment regulates attentional biases to threat; Cultural variations may impact on pathways to post-trauma recovery and the efficacy of various treatment strategies, such as group therapy or harnessing of social support.